Improvement in pistons for steam-engines



N;P0UST Piston for Steam Engines.

No. 201,661. Patented March 26,1878. K

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- I ATTDRNEY?! n N. PETERS, PNOTO-LITHOGRAPHER, WASHINGTON. D. C-

UNITED STATES PATENT OFFICE.

NATHANIEL FOUST, OF EDENBURG, PENNSYLVANIA.

IMPROVEMENT IN PISTONS FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 201,661, dated March26, 1878; application filed July 19, 1877.

To all whom it may concern.-

Be it known that I, NATHANIEL FOUST, of Edenburg, in the, county ofClarion and State of Pennsylvania, have invented certain new and usefulImprovements in Piston-Heads; and do hereby declare that the followingis a full, clear, and exact description thereof, reference being had tothe accompanying drawings, and to the letters of reference markedthereon, making a part of this specification.

The nature of my invention consists in the construction and arrangementof a piston for steam-engines, as will be hereinafter more fully setforth.

In order to enable others skilled in the art to which my inventionappertains to make and use the same, I will now proceed to describe itsconstruction and operation, referring to the annexed drawing, in which--Figure l is a perspective view of my improved piston; Fig.2, a sectionof the same through the line w m, Fig. 1; and Fig.3, a sec tion throughthe line y y, Fig. 2.

My piston is composed of a cup, A, with head or cover B and split oropen rings 0 O, surrounding the body of the cup or piston.

In the center of the cup A is formed a hollow post, D, through which thepiston-rod is passed, and fastened by a nut on the end, whereby the headB is also secured in place. An annular chamber, E, is thus formed insideof the piston.

In the heads of the piston are made valveopenin gs a to, directlyopposite each other, said valve-openings being countersunk on theinside, as shown in Fig. 2.

G is a double valve, placed in these countersinks and guided by them, toadmit steam into the chamber E from either end, according to which sidethe steam is acting on, and, of course, close the other opening.

In the under side of the piston A are made stroke or dead-center of theengine, and thence passes into the eccentric grooves d, forcing therings outward and packing the piston.

It will be understood that the piston-head is at all times full ofsteam, which, of course, exerts an equal pressure in all directions;hence the piston rests on the bottom of the cylinder simply with theforce of its own weight. The steam escaping through the bottom of thepiston into the eccentric grooves naturally draws the packing-ringsdownward, making a tight joint at the top between said rings and thepiston, so that the steam cannot pass entirely around the piston.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

The combination of the hollow piston A B, provided on its under sidewith ports I), and in its exterior with grooves d, tapering from thebottom toward both sides and extending only partially around the'piston, the packingrings 0, and interior valve Gr, all constructedsubstantially as and for the purposes herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand this29th day of June, 187 7.

NATHANIEL FOUST.

Witnesses:

FRANK GALT, J. H. WAssorL,

